Comparison of optical sensors for non-invasive hemoglobin measurement

Abstract

Anaemia, a deficiency of hemoglobin content in blood is spreading worldwide. Hemoglobinometry is a regular test performed on practically every patient. Non-invasive hemoglobin measurement techniques do not require blood sample, reducing patient discomfort, infections and helps in faster diagnosis. Presently there is a need for a universally accepted non-invasive hemoglobin measurement device. An electro-optical in vivo approach for hemoglobin concentration measurement is presented in this paper. Two inputs are required, Impedance Plethysmography (IPG) which determines segmental blood volume and optical sensor Photoplethysmography (PPG) which determines the absorbance of light depending upon mass of blood constituents. This paper shows work on PPG. Two optical sensors photodiode (OPT-101) and phototransistor (SFH 3310) have been used with for a wavelength of 530nm, green light and their graphs have been obtained on LABVIEW. Both these sensors give voltage as output. Ratio of these two measurements can be related with Hemoglobin concentration.